The present invention relates to a vehicle travel control apparatus, and more particularly, to a vehicle travel control apparatus suitable to control a distance between vehicles and a vehicle speed.
Conventional vehicle travel control apparatuses measure, for example, a distance between a one"" vehicle and a vehicle traveling ahead and control a degree of opening of a throttle valve or a brake so that the distance between the vehicles is kept constant in accordance with the vehicle speed of the one""s own vehicle. Further, the vehicle travel control apparatuses control a degree of opening of the throttle valve or the brake so that the one""s own vehicle keeps a constant vehicle speed.
However, it has become apparent that when a vehicle was actually traveled on a road using the conventional vehicle travel control apparatuses, the control performance of the apparatuses were lowered depending upon a state of the road. For example, when a road was curved or began to ascend, the conventional vehicle travel control apparatuses started to control a distance between vehicles and a vehicle speed after they detected a change of state of the road based on a change of a vehicle speed, and the like, which caused a time lag until a proper control was actually executed because the start of control was delayed. As a result, it has become apparent that a problem arose in that the conventional vehicle travel control apparatuses could not smoothly control a vehicle. For example, when a vehicle comes to an upward slope, the speed of the vehicle is reduced and the apparatuses increase the speed of the vehicle after they detect the reduction of the speed, which sometimes makes it difficult to keep the vehicle at a constant speed. In particular, as the slope of a road is more steep, a response is more delayed. Further, while a vehicle must reduce a speed when it makes a turn, a time lag is caused until the speed is actually reduced.
To cope with the above problems, the inventors examined a system for improving the controllability of a vehicle control apparatus by predicting a change of state of a road making use of data of curves and slopes stored in position information displays which are typically a car navigator. For this purpose, the inventors examined a system for associating a position information display with a vehicle control apparatus and for sharing the information of the respective apparatuses. When the information of the plurality of apparatuses having a different function was shared, the inventors examined a system for simultaneously sharing the information using serial communication to reduce the number of communication lines that connect the plurality of apparatuses.
However, when the serial communication is used to share the information of the plurality of apparatuses, a task is necessary to share the information. In particular, it has become apparent that the quantity of information to be shared is increased in a system which aims at the provision of a high-grade drive support system, and thus when the serial communication is used in the system, it is difficult to execute a control while sharing the information because a communication task becomes longer than the tasks which are necessary to realize the intrinsic functions of the respective apparatuses.
Accordingly, an object of the present invention is to provide a vehicle control apparatus which makes it possible to share information by a plurality of apparatuses and by which controllability can be improved.
(1) To achieve the above object, the present invention includes a plurality of operating systems, an OS switching means for switching the plurality of operating systems, and a shared object (CO) having a memory resource which can be referred to from the plurality of operating systems, wherein the shared object (CO) shares at least road information, and the road information registered by the application of one of the operating systems can be referred to from the application of the other operating system.
With this constitution, information can be shared by a plurality of devices, which improves controllability.
(2) In the above (1), it is preferable that while one of the operating systems registers road information to the shared object or refers to the road information, the shared object (CO) prohibits the other operating system from register road information to the shared object or from referring to the road information.
With this constitution, reference to incorrect information can be prevented when road information is registered to the shared object or referred to from the other operating system.
(3) In the above (1), it is preferable that when one of the operating systems registers road information to the shared object or refers to the road information, the shared object notifies the other operating system that road information is registered to the shared object or the road information is referred to.
With this constitution, the application of the other operating system can recognize that road information has been renewed.
(4) In the above (1), it is preferable that the application of one of the operating systems analyzes a signal received through broadcasting or communication and extracts road information as well as registers road information to the shared object, and the application of the other operating system controls the traveling speed of a one"" own vehicle referring to the road information registered to the shared object.
(5) In the above (4), it is preferable that the application of one of the operating systems analyzes the signal received through the broadcasting or the communication and extracts information added to the road information as well as registers the added information to the shared object, and the application of the other operating system controls the traveling speed of the one""s own vehicle referring to the road information and the added information registered to the shared object and to the traveling environment information of the vicinity of the one""s own vehicle.
(6) Further, to achieve the above object, the present invention includes a plurality of operating systems (OS1, OS2) and a shared object (CO) having a memory resource which can be referred to from the plurality of operating systems, wherein the shared object (CO) shares at least road information, and the road information registered by the application of one of the operating systems can be referred to from the application of the other operating system.
(7) In the above (6), it is preferable that while one of the operating systems registers road information to the shared object or refers to the road information, the shared object (CO) prohibits the other operating system from register road information to the shared object or from referring to the road information.
(8) In the above (6), it is preferable that when one of the operating systems registers road information to the shared object or refers to the road information, the shared object (CO) notifies the other operating system that road information is registered to the shared object or the road information is referred to.
(9) In the above (6), it is preferable that the application of one of the operating systems analyzes a signal received through broadcasting or communication and extracts road information as well as registers road information to the shared object, and the application of the other operating system controls the traveling speed of a one"" own vehicle referring to the road information registered to the shared object.
(10) In the above (9), it is preferable that the application of one of the operating systems analyzes the signal received through the broadcasting or the communication and extracts information added to the road information as well as registers the added information to the shared object, and the application of the other operating system controls the traveling speed of the one""s own vehicle referring to the road information and the added information registered to the shared object and to the traveling environment information of the vicinity of the one""s own vehicle.